NEET BIOLOGY

Detailed explanation-1: -One important light response in plants is phototropism, which involves growth toward-or away from-a light source. Positive phototropism is growth towards a light source; negative phototropism is growth away from light.

Detailed explanation-2: -Growth or movement towards a light source is positive phototropism. Stem and leaves show positive phototropism whereas root shows negative phototropism.

Detailed explanation-3: -Phototropism, or the differential cell elongation exhibited by a plant organ in response to directional blue light, provides the plant with a means to optimize photosynthetic light capture in the aerial portion and water and nutrient acquisition in the roots.

Detailed explanation-4: -Sunflowers are a great example of positive phototropism, because not only do their stems curve toward the light but their flowers turn to face the sunlight as well.

Detailed explanation-5: -“Photoperiodism” is defined as “The response to changes in daylength that enables plants (or any other living organisms) to adapt to seasonal changes in their environment.”